[Brian Cheney]

As most visitors here know we are undertaking the ambitious project of a live-vs-recorded demonstration at the next CES and have rented the Zeus Ballroom of the Alexis Park Hotel for this purpose.

Since initiating the project about one month ago I have corresponded with knowledgable and experienced recordists asking for their counsel and advice.  I lack experience with today's digital storage media and modern microphones, as I did my live recording 25 years ago and have the LP's to prove it.

Most of my inquiries met with stoney silence or outright derision.  "Can't be done!" is the most frequently voiced opinion amoung some well known engineers.  Indeed the whole concept of a successful "live-vs-recorded" demo appears to be a one-way ticket to audio palookaville, when all I really want is to be a contenda.

However, I have had a most valuable exchange of emails with a well-known recordist to whom I will refer only as "Mystery Engineer".  His insights and information will be of interest to many audiophiles on this board, so I will now refer everyone back to the "Ampzilla, VMPS and Live Music at the 2009 CES" thread where the "Problem of the Two Acoustics" will  be addressed, among other topics. The first installment begins today.

[Brian Cheney]

Well, in yesterday's Part I of our subject matter we learned (much to our chagrin) that there are problems involved in recording and playing back in the same room, the primary problem (that of the Two Acoustics) being that, regardless of the quality of the playback system, if we do not do something to change the playback environment (primarily, but not exclusively, its reverb time RT60) there will be too much "ambience" in the playback the audience hears, and the reproduced sound will not be very "real" to them.

We have had some excellent suggestions and observations from AC'ers.  In today's Part II, our Mystery Engineer has surprising suggestions to address the fundamental dilemma.

Audiophiles note: a good listening room, we now know, has a reverb time of no more than 2/3 second and should have an RT60 that is less than half that of the reverb time of the recording environment.  So, go into your listening room and clap your hands sharply while walking around.  Any buzz or echo means some damping is in order.

I'll ask John Casler to install a direct link to "Ampzilla, VMPS and Live Music at CES" on this teaser thread for the convenience of our viewers.

[John Casler]

I'll ask John Casler to install a direct link to "Ampzilla, VMPS and Live Music at CES" on this teaser thread for the convenience of our viewers.

Done:

This takes you to the thread from the beginning:

http://www.audiocircle.com/index.php?topic=53843.0


This takes you to the present engineering discussion:

http://www.audiocircle.com/index.php?topic=53843.40

[Brian Cheney]

Well, we've been at an impasse for a week or so on this matter.

Advice from my Mystery Engineer can be summarized as follows:

1. You'll have to experiment.  Be smart about it, find a similar environment locally, and try various solutions using volunteer performers and several different approaches.
2. Don't expect the world's best results.  People with a lot more money and experience have failed in the live-vs-recorded endeavor.

OK, let's concentrate on just the playback environment.  From my recording experience I found the most revealing monitor device to be headphones.  In olden days I used the two-way Superex model with the pieze tweeter (new and revolutionary back in the early 70's).  Headphones obvisouly add nothing to the ambience of playback environment.

So I propose the following solution to the Problem of the Two Acoustics:

GIANT HEADPHONES

This means: speakers and listeners close together for nearfield listening, cocooned by reflective and absorbtive panels which create an effective "between the ears" acoustic with little to no reverberation added to the room ambience already in the recording.  It does involve  moving isolation panels into place during playback, and taking them away during recording.

Comments?

[Hipper]

Again please excuse my impertinence, but I think you should focus on what you are really trying to achieve here.

If it is merely an academic exercise in trying to reproduce exactly what listeners heard then carry on!

However, I would have thought your ultimate aim is to show that your speakers are what people want in their listening place, so they buy them. This surely means that you have to use set ups that most of your potential purchasers can employ themselves.

If you use some impractical arrangement that gets people saying 'wow' but they still don't buy your speakers, would you be happy?

[Housteau]

So I propose the following solution to the Problem of the Two Acoustics:

GIANT HEADPHONES

This means: speakers and listeners close together for nearfield listening, cocooned by reflective and absorptive panels which create an effective "between the ears" acoustic with little to no reverberation added to the room ambiance already in the recording.  It does involve  moving isolation panels into place during playback, and taking them away during recording.

Comments?

A good friend of mine with a nearly identical listening space as I have, in fact I built mine after experiencing his, listens in this way.  It can be very vivid, but it has some negatives that personally I cannot get around.  While the image, focus and sound in general between the speakers is quite convincing and possibly the best I have heard, there is little to be had to the outsides of the speakers.  This makes for a narrow soundstage and I don't like that at all, especially after being able to experience one closer to full scale.  So, I don't really care how accurate he can get the middle when the price is the loss of the outside edges.

One other huge negative to me is the appearance.  Here is this nice sized room and he is using these large speakers as headphones.  That really bothers me just to look at it like that.  It also creates a very upfront sort of sound and I prefer mine just a bit more away from the tip of my nose.

I hope that there is another better solution to this problem of acoustics.  You now have access to a nice sized room at the CES with all the potential in the world for setting up this V60 / VLA system to really open a lot of eyes and ears this time around.  This system is capable of such a large presentation and this space will allow an ideal set-up.  My concern is if the playback system needs to set up a particular way just for the attempt of recreating the live performance, then it could be highly compromised for standard playback of customers CDs and other prerecorded music.    Some attendees may be confused by this not fully understanding the what and why of it all, and just leave with the impression of bad sound.  If that happens, then a great opportunity will have been lost.

I see the best solution as one that allows full fidelity for both types of playback.

[Early B.]

I see the best solution as one that allows full fidelity for both types of playback.

Bingo!! 

Even if the project were successful, I'm not sure it really proves anything. At best, the experiment can show what is possible, not practical. I don't have a team of audio experts, a big budget, a huge room, and the best audio gear on the planet in my house to improve the sound of my speakers.

I'm not trying to piss on the project. I agree with Hipper -- if you're at a stalemate, the solution lies in revisiting the goals.

 

[Early B.]

I wanted to add one more thing -- one of the reasons I'm a proud owner of VMPS speakers is the tweakability factor. I'm not sure many audiophiles fully appreciate the value of tweaking speakers. One thing that would be really cool to demonstrate is the ability of VMPS speakers to be tweaked based on various simulated acoustic environments that mimic some of the typical issues we encounter with our listening rooms. CES 2010, maybe?

 

[Brian Cheney]

OK, the "giant headphones" idea is a little creepy, I admit.

We still need to reduce the reverb time of the ballroom by about half during playback only.

Suggestions?

[Russtafarian]

How high are the ceilings?  Would it be possible to suspend acoustic panels over the listening area to diffuse and/or absorb early reflection points off the ceiling?  That would reduce the acoustical space.

Russ

[Brian Cheney]

Ceilings are 14ft in the Zeus Ballroom.

While we may indeed add absorption to the ceiling, the acoustic would still be the same for recording and playback.  What we need to do is reduce reverb time during playback only, and then restore it during recording.

Side wall treatments that are reversable appear the best solution I can come up with.

[John Casler]

This quandry is generally what I am usually "preaching" when I post to "room treatment" threads.

So many of the "acoustics experts" treat playback rooms and listening rooms the same.

That does not give an "Original Sound" accuracy.  It gives the "sonic tale of two rooms" that overlay each other. (even if it is the same room)

It would be great, if we could wheel suspended "sound blankets" to the sides and rear of the listeners much like my "listening chamber" but on a larger scale.

That would help a bit if you could make the frequencies affected wide enough.

Just thinking out loud if the recording were "close" miked to each performer to reduce the "room" in the recording and then the speakers were set at the "exact" same distance from the listeners, so that the recreated sound was sent out into the room with same distances, the results should be rather similar.

The whole idea however rests on the aspect that the recording NOT have much room sound.

This way the listeners "hear" the performers "in the room" and then they also "hear" a closed miked reproduction "and" the room interaction similar to the the perfromers from the exact same distances in the room.

I hope that makes sense.

Looks like the best bet without some exceptionally tricky and extensive acoustic treatment.

[sixstringer99]

My thoughts as an audio consumer and long time/part time musician may only be worth two cents but here it goes.  Trying to record the music live in-situ and then attempt to play back that recording for the audience over VMPS equipment does not make sense to me.  Sorry.  What I suggest (here is the two cents) is record the band live in a controlled professional studio for the best live sound.  Use that as the playback recording.  Have the same band play live at the CES in the "Big Room" the same music that was recorded earlier in the studio.  If the comaparison of the studio recording played over the VMPS V60's and the live sound are identical, then you have achieved your goal.  Or what I would presume should be your goal.

The original goal sounds more like you want to be a recording engineer.  There are a lot of variables when recording music considering room acoustics, microphones, electronics/sound boards etc in the recording chain.  Optomizing for recording and optomizing for playback are two different animals.  If you compromise both for the sake of this experiment I don't think you will be happy with the final product.  Most audio consumers, even audiophiles, probably won't understand the recording chain and playback chain compromises either.  It is an ambitious goal however, good luck with whatever you decide.  Again, I would be happy with a really live sound comparison without the real time recording.

[BobMajor]

I agree with sixstringer. Ever since you announced this ambitious experiment I have been concerned that you would be spending an awful amount of money with very disappointing results.

[lifewithmusic]

I agree with BobMajor and Hipper.

Brian, I suggest that you are at the point where you need to conduct an experiment in some space local to you.  I, for one, will be very interested in your results.